The monitoring of trace metals in tissues from organisms exposed to environmental contaminants in water, air, and other sources, including exposed human and animal tissues such as urine, blood, lung and other organs, plays an important role, not only in the assessment of normal biological metabolic functions, but also as an indicator of exposure to toxic materials and to gain a better understanding of sources of environmental contamination and mechanisms of resulting disease. Traditionally, metal analysis in exposed tissues has been accomplished by graphite furnace atomic absorption (GFAA), which has been in existence for the past several decades at NYULMC (NYU Langone Medical Center) via the Molecular Cell & Analytical Services Facility Core of the NYU NIEHS Center, as well as via formal collaboration within the Animal Exposure Facility Core/Metals Analysis Unit of the NYU Cancer Center. However, when large numbers of samples are analyzed for multiple elements, and when the detection limits are reached by lower, more human-relevant environmental exposure levels, GFAA either becomes very cumbersome and restrictive since it can only determine one element at a time, or it fails completely owing to the limits of detection being higher than the measurable sample levels of the metals of interest. Thus, the detection capability of Inductively Coupled Plasma Mass Spectrometry (ICP-MS) for many clinically significant elements is far superior to GFAA, and can only be accomplished using sensitive ICP-MS equipment. This proposal outlines the growing needs for ICP-MS in the monitoring of human health effects of a wide variety of environmental exposures in a variety of matrices, both in human populations around the world, and in laboratory-exposed animal models of disease and disease mitigation.